natural rubber ppt

1. NATURAL
RUBBER
PRESENTED BY-
GROUP 9

2. NATURAL RUBBER
• Natural Rubber is obtained as a milky white
fluid known as Latex (It is a complex emulsion
consisting of Proteins, Starches, Sugars, Oils,
Resins and Gums).

3. What is Rubber ?
• Rubber industry is a very recent industry, less
than 100 years.
• Chemically, rubber is polyterpene, consisting
of long (50-500) of isoprene units joined end
to end to form giant molecules called
polymers, which are coiled up like tiny springs.

4. PARA RUBBER

5. Morphology of the rubber yielding plant Hevea brasiliensis
• Hevea brasiliensis is a stout fast growing profusely branched
tree.
• It grows up to height of 40 meter but commercially, its height
is allowed to grow up to 20 meter.
• The girth of its trunk is about 2-3 meter at the base.
• Leaves are compound which are trifoliate.
• The leaflets are elliptical with acute apex.
• Flowers are small, green, unisexual having pleasant fragrance.
• Inflorescence is pencil.
• Fruit is capsule type which is tripartite.

6. Leaves of Para rubber

7. Trees of Para rubber

8. Manufacturing process of Rubber
Natural Rubber is obtained from latex which is
a milky substance produced by a rubber
yielding plant.
Tapping and Processing are the main steps of
the manufacturing process of rubber.

9. (A) TAPPING
• In this step a number of V-shaped incisions are made in the
bark of rubber yielding plant by the help of a special knife.
• These incisions are made only on one side of the trunk at a
time from top to bottom.
• Tapping is usually done during morning hours.
• The latex is collected in earthen pots by keeping them just
below the incisions.
• Anticoagulant like Hydrogen peroxide or ammonia are added
to the pot to check the coagulation of latex.
• The coagulated latex which is found attached to the incisions
is collected separately from which low quality rubber is made.
• Next Tapping is done on either side of trunk normally after 1-2
years.

10. Image showing Tapping process

11. (B) Processing
• The latex obtained is first passed through a large aluminium
sieve to remove impurities like pieces of bark and leaves.
• Then the water content present in latex is measured with
hygrometer.
• Then the latex is allowed to coagulate in a large container.
• The coagulation of latex is done by constant stirring and
adding formic acid and acetic acid.
• The coagulated rubber is washed with water and then the
water is squeezed out by pressing it through roller. This thin
rubber sheet formed id known as crepe rubber.
• The ‘crepe rubber’ is translucent, brown, elastic and rubber.
• Rubber is mostly exported in the form of sheet rubber.

12. Image showing Processing

13. • Vulcanization of sheet rubber is required to increase
its elasticity, tensile, strength and resistance. It is
done by heating the sheet rubber by maintaining the
temperature at about 50 degree celsius with the
addition of suitable amount of sulphur, selenium and
nitrogen.

14. Uses of Para Rubber
• About 70% of rubber produced is utilized in making tires, tube
and other articles associated with the automobiles.
• It is also used in making electrical goods, waterproofed
materials and sports good.
• The hand globes used in electricity and hospital are made of
rubber.
• Hard rubber is mostly used in electrical and radio engineering
industries.
• Sponge rubber is used in carpeting.
• Rubber belt is used for transportation of breakdown vehicle.
• Different agricultural products are made of rubber.